double centering

16 LETTERS · STARTS WITH D

double centering is a valid 16-letter word worth 21 points in Scrabble and 28 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

D2O1U1B3L1E1C3E1N1T1E1R1I1N1G2

2 + 1 + 1 + 3 + 1 + 1 + 0 + 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 2 =21 PTS

DOUBLE WORD → 42TRIPLE WORD → 63

MEANING

What does double centering mean?